[plt-scheme] Does anyone use `set!' and `get!' patterns?

On Wed, Mar 12, 2008 at 4:21 PM,  <hendrik at topoi.pooq.com> wrote:
>
> On Tue, Mar 11, 2008 at 09:59:13AM -0400, Sam TH wrote:
>  > On Tue, Mar 11, 2008 at 9:36 AM, Eli Barzilay <eli at barzilay.org> wrote:
>  > > This is probably the original motivation for this feature.  For
>  > >  example, with the generic setters in Swindle, you get
>  > >
>  > >   (inc! (cadddr x))
>  > >
>  > >  to expand to
>  > >
>  > >   (set-cadddr! x (+ (cadddr x) 1))
>  > >
>  > >  and my guess is that with the match setters, it would be like doing
>  > >
>  > >   (let ([x (cdddr x)]) (set-car! x (+ (car x) 1)))
>  >
>  > Right.  Something like:
>  >
>  > (match x
>  >   [(list-rest c _ _ (set! x!)) (x! (+ c 1))])
>
>  That looks useful!  If, that is, the objects in question are mutable.

You might think so.  But after at least 5 years, it seems to have
gotten no use at all.  Do you have any particular uses in mind?

Thanks,
-- 
sam th
samth at ccs.neu.edu